Inheritance relation creates left outer join in stead of inner join btwn child and parent ----------------------------------------------------------------------------------------- Key: HHH-5613 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-5613 Project: Hibernate Core Issue Type: Improvement Components: core Affects Versions: 3.5.4 Reporter: Marc Schipperheyn Priority: Minor I have @Entity @Table(name = "Offer") @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorValue(value = "OFF") @DiscriminatorColumn(name = "DTYPE", length = 3) public class Offer @Entity @DiscriminatorValue("JOB") @SecondaryTable(name="JobOffer", pkJoinColumns = { @PrimaryKeyJoinColumn(name = "offerId", referencedColumnName = "offerId") } ) public class JobOffer extends Offer When I run a detached Criteria query DetachedCriteria dc = DetachedCriteria.forClass(JobOffer.class) .add( Restrictions.in("id", ids)); return getHibernateTemplate().findByCriteria(dc); I see in the query something like this from Offer this_ left outer join JobOffer this_1_ on this_.offerID=this_1_.offerId where this_.DTYPE='JOB' and this_.offerID in (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) It would seem to me that it would make more sense to have an inner join here b/c JobOffer is a child of Offer and therefore must have a table relationship. Every row in JobOffer table should have a corresponding row in Offer table. I would imagine that an outer join performs less than an inner join because the amount of rows evaluated would be less. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira